Secondary Amenorrhea (Gynecology)

00:01 Let's now talk about secondary amenorrhea.

00:03 You've had a period once but now it's gone.

00:07 That's secondary amenorrhea as supposed to primary amenorrhea, which means you never had a menstrual cycle.

00:13 Secondary amenorrhea is defined as no period for 3 cycle lengths or for 3-6 months.

00:19 That's atypical, something has gone wrong and now it's our job to find out what.

00:25 Let's now list the common causes of secondary amenorrhea.

00:30 When you have a low or normal FSH, it can be due to weight loss, so if you've lost weight in a very quick time your FSH might be quite low.

00:40 If you have an eating disorder such as anorexia or perhaps bolemia, your FSH is low.

00:46 You can have non-specific hypothalamic amenorrhea, for some reason your hypothalamus just stops firing and your anterior pituitary does not release gonadotropins.

00:57 A very common cause is chronic anovulation including PCOS.

01:01 For more information about PCOS there's a lectures about that.

01:05 You can have it with hypothyroidism, so that's when your thyroid is not functioning as it should be.

01:11 You can also see a normal or low FSH with Cushing's Syndrome.

01:16 A pituitary tumor or an empty sella or Sheehan syndrome can also cause a low or normal FSH.

01:24 Let's talk a little bit about Sheehan Syndrome.

01:27 Sheehan Syndrome is often tested on a USMLE.

01:31 It usually occurs after a postpartum hemorrhage.

01:35 Postpartum hemorrhage still occur as worldwide and is a number one cause of maternal death.

01:40 In the US, it's less so but with Sheehan Syndrome you get pituitary apoplexy because of Pituitary loses blood flow during a postpartum hemorrhage.

01:50 These women typically cannot lactate postpartum and they also lose their axillary hair and they never have return to menses.

01:57 So watch out for this on your exam.

01:59 Let's not talk about high FSH as a cause of secondary amenorrhea.

02:04 This can occur with 46, XX individuals who have primary ovarian insufficiency or you can have an abnormal karyotype that leads to early cessation of menstrual cycles.

02:15 This is the case with Turner Syndrome patients.

02:18 The majority of cases with Turner Syndrome presents with primary amenorrhea.

02:25 Secondary amenorrhea appears in less than 10% of patients usually in those who carry up partial deletion of the X chromosome or have sex chromosome mosaicism.

02:37 You can also have a high prolactin that causes secondary amenorrhea.

02:42 There is another lecture set that you can download to learn more information.

02:46 There are also anatomic causes of secondary amenorrhea.

02:50 This is the case in Asherman Syndrome, you typically see Asherman Syndrome after pregnancy where some type of dilation and curettage has occurred.

02:59 This can occur as a result of a postpartum hemorrhage or post-abortal.

03:04 These adhesions, because the uterus to actually have adhesions between the two walls and can obstruct any menstrual flow.

03:11 You can also find secondary amenorrhea in hyperandrogenic states.

03:17 This happens with an ovarian tumor, non-classical congenital adrenal hyperplasia and also undiagnosed hyperandrogenism.

03:26 There are a lot more causes but we're going to review just the large ones here, functional hypothalamic amenorrhea is actually the most common cause of secondary amenorrhea.

03:39 You can also have hyperandrogenism and polycystic ovarian syndrome.

03:44 Hyperprolactinemia is third, premature menopause or ovarian insufficiency comes in fourth.

03:51 Asherman's Syndrome is last and then you can have other uncommon causes of secondary amenorrhea.

03:58 But I wouldn’t worry so much about those in your USMLE. Try to remember the above.

04:03 Now, we'll go over what we should do when a patient presents with secondary amenorrhea.

04:09 First, you need to complete a thorough history and physical examination.

04:14 Second, don’t forget to rule out pregnancy as this is a common cause in the reproductive age.

04:20 Third, we need to get an FSH, usually in conjunction with an estradiol, on the third day of the menstrual cycle and a prolactin.

04:28 A prolactin needs to be taken in the AM and fasting.

04:32 If the FSH is actually equivalent or not higher or not low, you should suspect an anatomic defect such as Mullerian, a genesis or dsygenesis.

04:44 If the prolactin is high you should do a radiographic evaluation for prolactinoma.

04:51 Unless, there is an obvious cause as to why the prolactin is high.

04:54 Again, there is another lecture that you can listen to that talks about prolactin.

04:59 If the FSH is elevated, this can indicate ovarian failure or ovarian insufficiency.

05:06 This is seen in gonadal dysgenesis.

05:08 If the FSH is low or equivocal, this can mean chronic anovulation as you see with PCOS and functional hypothalamic amenorrhea.